The Ad Hoc network is a special wireless mobile network, in which all the nodes are equal in status, so that no central control node is needed. The nodes in the network not only have a function required by a common mobile terminal but also have a packet forwarding function.
Generally, the Ad Hoc network has two structures: a planar structure and a hierarchical structure. The planar Ad Hoc network, in which all the nodes are equal in status, may also be called a peer-to-peer structure, while the hierarchical Ad Hoc network is divided into clusters each consisting of one cluster head and a plurality of cluster members. In the hierarchical Ad Hoc network, the cluster head node is responsible for data forwarding between clusters. The cluster head may be pre-assigned or automatically selected by the nodes by an algorithm.
The hierarchical Ad Hoc network may also be divided into a single-frequency hierarchical network or a multi-frequency hierarchical network. In the single-frequency hierarchical network, all the nodes communicate at one frequency and need the support of a gateway node to communicate with the cluster head, namely, needing the support of a node which belongs to two clusters at the same time, while in the multi-frequency hierarchical network, different nodes communicate at different frequencies. In a two-level network, the cluster head node has two frequencies, one of which is for the communication between a cluster head and a cluster member, and the other of which is for the communication between two cluster heads. The Ad Hoc network of the planar structure is very simple, and all the nodes in the network are completely equal, so that no bottleneck exists in principle and a failure may not occur easily. In the Ad Hoc network of the hierarchical structure, the cluster members have a very simple function and do not need to maintain complex routing information. The Ad Hoc network of the hierarchical structure has the defects that the nodes need to execute cluster head selection algorithm for the maintenance of the hierarchical structure and the cluster head node may become a bottleneck of the network. Therefore, when the network is on a small scale, the Ad Hoc network of the planar structure may be applied; and when the network is on a large scale, the Ad Hoc network of the hierarchical structure is applied. The disclosure is described based on the Ad Hoc network of the planar structure.
With the improvement of living standards of people, the demand for tourism is growing and the requirement on the touring environment is also rising. At present, a scenery area usually includes multiple scenery spots, which are far from one another. A tourist may prefer to visit a scenery spot where there are fewer tourists during the travelling. Whereas, in the existing technology, only the number of tourists at the whole scenery area can be counted and the number of tourists at each scenery spot cannot be counted, thereby, such requirements of users cannot be met.